The project is concerned with the synthesis and study of analogs of glycerolipids in which the glycerol backbone is replaced by each of the isomeric cyclopentane-1,2,3-triols. Some of these have been prepared already. The analogues of tris-homoacyl triglycerides will be investigated as substrates for pancreatic and other lipases in monolayer dispersions. The molecular areas of these compounds will be measured. Analogues of 1,2, and 1,3 diglycerides and the corresponding mixed-acyl analogues of triglycerides will be synthesized. Analogs of phosphatidic acid will be used to synthesize corresponding analogs of phosphatidyl choline and phosphatidyl ethanolamine. Present syntheses involve only C16:0 fatty acids. Synthesis of several shorter chain analogues will be undertaken. Corresponding analogs of glycerol phosphate will be prepared. When available they will be used as probes for rotational specificity of glycerol phosphate in the enzyme-catalyzed reaction: CDP diacyl glycerol plus glycerol-P yields phosphatidyl glycerol-P plus CMP.